Lunar highlands breccias generated by major impacts

The processes that may have been involved in the formation of most of the major types of lunar breccias are discussed. Some of the types of highlands breccias that may have originated in large impacts are identified

The ancient lunar crust, Apollo 17 region

The Apollo 17 highland collection is dominated by fragment-laden melt rocks, generally thought to represent impact melt from the Serenitatis basin-forming impact. Fortunately for our understanding of the lunar crust, the melt rocks contain unmelted clasts of preexisting rocks. Similar ancient rocks are also found in the regolith; most are probably clasts eroded out of melt rocks. The ancient rocks can be divided into groups by age, composition, and history. Oldest are plutonic igneous rocks, representing the magmatic components of the ancient crust. The younger are granulitic breccias, which are thoroughly recrystallized rocks of diverse parentages. The youngest are KREEPy basalts and felsites, products of relatively evolved magmas. Some characteristics of each group are given

Systemic banking crises

Systemic banking crises can have devastating effects on the economies of developing or industrialized countries. This Policy Discussion Paper reviews the factors that weaken banking systems and make them more susceptible to crises.Financial crises ; Bank failures

Industrial loan companies

Once Wal-Mart announced its intention to acquire an industrial loan company, a public furor arose that has brought a lot of attention to a type of institution that has existed for quite some time, but was not widely recognized outside of banking circles. What are ILCs and why have they become so controversial lately?Industrial loan associations

Heuristic Refinement Method for the Derivation of Protein Solution Structures: Validation on Cytochrome B562

A method is described for determining the family of protein structures compatible with solution data obtained primarily from nuclear magnetic resonance (NMR) spectroscopy. Starting with all possible conformations, the method systematically excludes conformations until the remaining structures are only those compatible with the data. The apparent computational intractability of this approach is reduced by assembling the protein in pieces, by considering the protein at several levels of abstraction, by utilizing constraint satisfaction methods to consider only a few atoms at a time, and by utilizing artificial intelligence methods of heuristic control to decide which actions will exclude the most conformations. Example results are presented for simulated NMR data from the known crystal structure of cytochrome b562 (103 residues). For 10 sample backbones an average root-mean-square deviation from the crystal of 4.1 A was found for all alpha-carbon atoms and 2.8 A for helix alpha-carbons alone. The 10 backbones define the family of all structures compatible with the data and provide nearly correct starting structures for adjustment by any of the current structure determination methods

Justice Holmes and Chancellor More

St. Thomas More Society Reports (Consistent with the policies of The Catholic University of America Law Review, summaries of papers read at the annual meeting of the St. Thomas More Society will be published from time to time. One summary is included in this issue.

Justice Holmes and Chancellor More

St. Thomas More Society Reports (Consistent with the policies of The Catholic University of America Law Review, summaries of papers read at the annual meeting of the St. Thomas More Society will be published from time to time. One summary is included in this issue.

Lunar highlands breccias generated by major impacts

Lunar missions are reported which have returned a variety of different types of breccias. These rocks differ greatly in their mechanisms of formation, source materials, and histories after formation; but all are related in that all were generated by impact processes. The impact processes involved in the formation of several major types of breccias are discussed. Some types that may have originated in large impacts are identified. Such breccias are extremely important. The impacts that formed them penetrated deeply into, and perhaps through the lunar crust and brought up materials that had previously experienced little or no impact modification. Detailed studies of such breccias can permit partial reconstruction of their preimpact source terranes and yield information on the nature of the early lunar crust (and possibly the upper mantle as well)